Method and apparatus for equalizing explosive charges in the different cylinders of multicylinder engines



Jan. 1926. 1,569,610

IZING EXPLOSIVE CHARGES IN THE F MULTICYLINDER ENGINES Filed March 5, 1920 A. P. BRUSH EQUAL METHOD AND APPARATUS FOR 2 Sheets-Sheet 1 DI FFERENT CYLINDERS O $1 Wmwu. lu /(M1 004% Jan. 1926. 1,569,610

A. P. BRUSH METHOD AND APPARATUS FOR EQUALIZING EXPLOSIVE CHARGES IN THE DIFFERENT CYLINDERS OF.MULTICYLINDER ENGINES Filed Marc h 5, 1920 2 Sheets-Sheet 2 H II e3 II 1 I 7 w, WW A dan mm.

' Patented Jan. 12, 19 26.

ALANSON' r. BRUSH, or'mrmorr, mrcnrem:

PATENT 0 FFlC-E. j

v METHOD AND AZPPARATU'S QIE'OR EQUALIZING EXPLO SIVE CHARGES IN THE DIFFER EN'I CYLINDERS OF MULTICYLINDER ENGINES.

- Application filed March 5, 1920. Serial No. 863,490.

To all whom it may concern:

Be it known that I, .ALANSON P. BRUSH, a citizen of the United States of America, re-

siding at Detroit, in the'county of Wayne of Multicylinder Engines, of which the following is a specification, reference bei'ng'had therein to theaccompanying drawings.

The invention relates to multi-cylinder internal combustion engines of the type in which the explosive mixture for the several cylinders is obtained from a single carburetor or mixing device. of the invention to avoid uneven operation, due to inequalities in the explosive charges introduced in the respective cylinders, or to changes in velocity of the current through the intake manifold. To this end the invention consists; first, in the method; and I second, in the apparatus, as hereinafterset forth.

In the drawings: I

Figure 1 is a side elevation showing a con-.. struction of intake for a multi-cylinder internal combustion engine embodying my invention; x y

Figure 2 is a plan view thereof;

'Fi re 3 is a vert'cal section on line 3-3 of F1gure-1.

In the resent state of the art in'the op eration of multi-cylinderexplosive engines having more than two cylinders difficulty is experienced in obtaining uniform quality of charges in the several cylinders, particularly when the engine is cold, as in starting. This is primarily due to the fact that the intake passages tothe several cylinders are not symmetrically arranged in the carburetor, or common portion of the manifold, and therefore the charge which. is introduced in one cylinder is subjected to different conditions than that introduced into another cylinder. Inasmuch as the liquid fuel is largelycarried in suspension by the air, there is a tendency for more of.

the fuel to be carried to one cylinder than.

to another, resulting in an over-rich mixture in the one and an over-lean mixture in the other. Thus some of the cylinders may misfire or develop less power than other cylinders. Another cause of. irregularity is due ,It is the object relation to to changes in velocity of the current pass- 1ng through the intake manifold, there" being a tendency for the liquid fuel to fall out of suspension when the current is traveling slowly and to be maintained in suspension under higher velocity.

With my lnvention the difiiculty is overcome by substituting for the unsymmetrical arrangement of intakes to the several cylin-. ders a symmetrical arrangement,.the construction being such that each cylinder receives 1ts charge under precisely similar cond1t1ons to that of the others. I have also provided "means for collecting and re-introducing the portion of the liquid fuel. which falls out of suspension during passage through the intake, thereb producing un1-' form mixtures when trave e nt velocities. Other features of theinvent1on relate to the means employed for obtaimng a comparatively homogeneous mixture of the air and liquid fuel.

In the construction shown, A is an intake manifold for a multi-cylinder explosion engine having morethan two cylinders and, as specifically illustrated, four cylinders. It is usual in four-cylinder engines to divide the manifold into two branches leading to ports in the engine block, from each of which there are two branch passages leading to different cylinders. With such an arrangement it has been found in practice that the fuel carried in suspension by the air current is not uniform, but more will be conveyed through one of the-'branch'passages than through the other. In other words, the mixture is not homogeneous and some portions of the air current are more heavily charged with the liopuid fuel than other portions. Therefore, during the changes of direction incident to passing through the'manifold, there will be a segregation of the heavily may derive its charge from the one and another from the other. v

To avoid this result, I first provide means for obtaining a fairly homogeneous mixture of the air and suspended fuel. Various spe cific constructions may purpose, but as shown,-the portion B of the mamfold receiving the charge directly from the carburetor is vertically arranged and is provided with an expanding portion Q and ng under diflerbe employed for this tiq'n C will slow the velocity of the current and where this .velocity is initially slow,

there will be a tendency for the suspended fuel to drop out at this point. 7 I, therefore provide means for. collecting the liqui which is thrown outand for vaporizing the same. and re-introducing into the air current without materially heating the air. This means specifically consists of an annular pocket E communicating with the manifold at the pointof greatest expansion 'C, the outer wall of said pocket being heated, 1preferably by being formed integral wit a portion F of the exhaust conduit. .The heated wall, as shown at G, is stepped and the liquid dropping down from one step to another will be completely vaporized and forced upward into the main passage. The pocket E is separated from the main passage by a flaring inner tube H and as this is out of mechanical contact with the heated wall and as the heat in said wall is .absorbed by evaporization of the liquid, ver little heat will be conducted into the main air current.

The effect of the construction just described is that when the engine is running at high s eed, or where the velocity of the current t rough the manifold is comparatively high, the liquid fuel in suspension Wlll be carried into the explosion chambers without pre-heating or vaporization, this being a de-. 'sirable condition to obtain the maximum power and speed from the engine. On the other hand, if the velocity of the current is comparatively slow,.a portion of the suspended fuel will drop out and after belng vaporized will be re-introduced into the main'current' so as to produce a more homogeneous mixture. The functions of the Venturi portion D of the passage is. to more thoroughly commingle the different portions of the current to increase the homogeneity thereof.

To maintain uniformity in the portions of the current which are drawn through the several cylinders, separate passages are provlded for each of the cylinders and the openings.

into these several passages are symmetrically arranged around the vertical portion B. Thus, as shown, I and I are branch conduits leading from the vertical conduit B to the ports J and J in the cylinder block, each of,

which supplies a pair of cylinders (not shown). K and K are division wallstin the branches I and I for dividing each into a pair of separate conduits, and L, L, L and L are segmental ports distributed around the vertical conduit B and communicating respectively with the separate conduits. Inasmuch as each of these segmental ports is in the same relation to the vertical portion of the manifold, it is evident that the explosive charge'passing through eaclr willbe the same in quantity and quality, which insures equal action in each of the engine cylinders.

The'exhaust manifoldM is preferably designed to' cooperate with the intake-mani fold and as shown is provided with the out-' wardly projecting portion F, which forms a section of the intake manifold, as previously described. The exhaust gases passing through this sectionwill maintain the step wall G at the proper temperature, so as to function in the mannerpreviously described. i

In operation, when the engine .is running at low speed, a portion of the liquid fuel in suspension will bethrown out of the ot' the venturi, or dropping into the annular pocket, and will eventually pass by gravity down upon the heated steps G. Here vaporization will take place and by expansion the vapor will be forced upward and comniingled with the main stream. In passing through the venturi D there will be a thorough commingling so as to produce a homogeneous mixture in the conduit above the point of greatest contraction. This ho- :rnogeneous mixture will be successively drawn into the different conduits formed by the branches I and I and the division walls viously described.

The effect of the venturi is to produce uniformity of mixture in all segments of the cross-section thereof around thecentral axis. Consequently, the current may be sub-divided into any number of divisions drawn off from different ,segments and in each division there will be the same quality of proportion of mixture. Thus the same construction can be used'for sub-dividing the current to any number of different cylinders, as well as to the four cylinders, as specifically shown in the drawin s.

What I c aim as my invention is:

1. The combination With a rriulti-cylinder internal combustion engine provided with more than two cylinders, of an intake conduit symmetrically sub-divided into separate branches leadingto the respective cylinders. 125

said means including a restriction in said conduit.

current, collecting on the contracting wall 1 2. The combination with a multi-cylinder internal combustion engine provided with more than two cylinders, of an intake manifold including a vertically extending conduit for receiving the explosive mixture directly from the carburetor, a venturi in said vertically extending portion for commingling the mixture passing therethrough, and a lurality of branch conduits symmetrical y arranged and connected into said vertical conduit and leading to the respective cylinders.

3. The combination with a multi-cylinder internal combustion engine provided with more than two cylinders, of an intake manifold including a vertical conduit directly connected to the carburetor, a portion of said vertical conduit expanded in diameter, means for collecting, vaporizing and returning to the main stream the liquid fuel drawn out of suspension in the expanded portion of said conduit, a venturi portion of said conduit beyond said expanded portion, and a plurality of separate branch conduits sym- 'metrically arranged and connected with respect to said vertical conduit and leading to t e respective cylinders. a

4. The method of operating multi-cylinder internal combustion engines, comprising the forming of a mechanical mixture of air and unvaporized fuel, passing said mixture through a venturi to obtain uniformity in proportion of ingredients in all symmetrical segments of the cross-section of the stream and in dividing the current in different segments of the cross section and leading the same to different cylinders.

5. The combination with a substantially vertical conduit having a venturi portion, of a pocket out of the path of the gaseous stream through said conduit and below said portion for collecting liquid fuel dropping out of suspension, and means for heating said xi ocket.

6. he combination with a substantially vertical conduit having a venturi portion and having an expanded portion below said venturi portion, of a pocket out of the path of the gaseous stream through said conduit and below said expanded portion. for collecting liquid fuel dropping out of suspen-. sion, and means for heating said pocket.

In testimony whereof I afiix my signature.

ALANSON P. BRUSH. 

